Dividers and Pencil Compasses

Dividers and pencil compasses are used to transfer measurements from the rule to the work and to scribe arcs and circles. They both have two legs joined at the top by a pivot. Dividers have both legs tapered to needle points whereas pencil compasses have one leg tapered to needle points. Dividers are more accurate and should be used to transfer critical measurements. In metals, the dividers are used only to scribe arcs/circles that will be removed later by cutting. All other arcs/circles are drawn with pencil compasses to avoid scratching the material

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The following are the steps and precautions to be followed when using dividers and pencil compasses.

• Ensure the points are sharp and should be protected by sticking them into a cork.
• Hold the divider/compass with the point of one leg in the graduations on the rule.
• Turn the adjustment nut with the thumb and forefinger and adjust the divider/compass until the point of the other leg rests on the graduation that gives the requirement measurement.
• To draw an arc/circle, hold the thumb attachment on the top with the thumb and forefinger. Swing the compass in a clockwise direction and draw the desired arc/circle, with pressure exerted on both legs.